A Call to End Routine Treadmill Stress Testing

By ANAHAD O'CONNOR

Published: July 31, 2012

Every year, hundreds of thousands of older Americans get on a treadmill in a doctor's office and walk or jog as an electrocardiogram monitors their heart function. But a growing number of medical authorities would like to make routine screening using the procedure, known as the treadmill or exercise stress test, largely a thing of the past.

On Monday, an expert government panel, the United States Preventive Services Task Force, joined the call by recommending against routine testing with electrocardiograms, or EKGs, in people who have no known risk factors or symptoms of heart disease, like shortness of breath or chest pains.

The recommendations, published online in Annals of Internal Medicine, made the test the latest addition to an expanding list of once routine screening tools that have fallen out of favor. Earlier this year, the task force advised against regular screening with the prostate specific antigen, or P.S.A., blood test, long considered the gold standard for early detection of prostate cancer. The panel has also come out against measures like annual Pap smears for many women and regular mammograms for women in their 40s.

For people at higher risk of heart disease, the panel found there was ''insufficient evidence'' to determine the benefits and harms of screening with the EKG test -- either at rest or during exercise -- and advised that it be considered case by case. In those instances, said Dr. Michael L. LeFevre, a vice chairman of the task force, patients should discuss with their doctors their medical histories and circumstances -- including age, blood pressure and cholesterol levels, and lifestyle -- to determine whether an EKG test might make sense.

The usefulness of the stress test has been questioned for some time, and in April, a group of nine medical specialty boards included it on its list of 45 common tests and procedures that doctors should perform less often. Their reasoning, like that of the task force, was that problems associated with the test can outweigh its benefit in many people, perhaps even leading to unnecessary harm.

''In my own practice I've seen people who thought they shouldn't be exercising anymore because someone put them on a treadmill and got an abnormal test result when in fact there was nothing wrong with them,'' said Dr. LeFevre. ''People get a false positive and can end up having a reaction to the subsequent angiogram or having something bad happen. Those things do happen.''

An underlying point of the new recommendations is that the emphasis should no longer be on screening people without symptoms, but on keeping coronary artery disease from developing in the first place, Dr. LeFevre said. ''We need to control blood pressure and cholesterol and get people to stop smoking and start exercising,'' he said.

Treadmill stress tests are relatively quick and cheap compared with more invasive tests, and some doctors believe they can identify people with narrowed arteries that put them at risk of having a first heart attack. But studies have shown that the cause of such heart attacks is usually the sudden rupturing of plaque, something the test is unable to predict. And when used on people who are at low risk for heart disease, false positive results can lead to unnecessary anxiety and more costly procedures, like a coronary angiogram.

Dr. Todd D. Miller, a cardiologist at the Mayo Clinic in Rochester, Minn., who has studied the test's effectiveness, said there were plenty of anecdotal reports about the treadmill stress test uncovering undiagnosed cases of heart disease, but no prospective studies bearing that out.

Still, he predicted the test would remain widely used. ''It takes a long time to see recommendations implemented in practice, and some of these old habits die hard,'' he said.